As appreciated by those skilled in the art, the contemplation, design, testing and manufacture of chemicals and biomolecules for administration to humans and animals, as nutritional or therapeutic agents, requires a thorough integration of clinically contemplated delivery principles and modalities. Chemicals and biomolecules that may be administered to humans and animals are often referred to herein as “actives,” “active ingredients” or “medicaments.”
Oral administration has become one of the most frequent routes for delivering one or more active ingredients or medicaments to the body. Active ingredients or medicaments, such as nutritional or therapeutic agents, may be orally administered in a variety of physical states (i.e., solid, liquid or gas). Tablets and capsules are generally the most common vehicle for the oral delivery of medicaments. As appreciated, a tablet may be broadly characterized as a compressed powder or granular solid. Prior to compression of the granular powder comprising the medicament into tablet form, the presence of one or more excipients may be required. An excipient includes any inert substance (i.e., gum arabic, starch or the like) combined with a principal ingredient to facilitate the preparation of an agreeable or convenient dosage form of the active or medicament. Functional characteristics of excipients may include, for example, disintegration, lubrication, appearance, palatability, shelf-stability or the like.
Those skilled in the art also developed capsules as a contrivance for containing a solid or liquid dosage form of a medicament. Traditional capsular embodiments include a first containment section referred to as a base, and a second containment section referred to as a cap. The two pieces of the capsule are usually formulated and designed in a manner such that the material to be encapsulated may be introduced into the base section, whereas the open end of the cap section may be correspondingly positioned over the open end of the base. The walls of the cap and base are generally in physical contact with one another to form a single internal cavity. A means for structurally sealing the cap in relation to the base may also be incorporated during manufacture to insure non-tampering of the capsule. In this regard, those skilled in the art developed sealing technology which contemplates banding, heat fusion (spot-welding) and snap seals which utilize a “tongue and groove” scheme.
The outer walls of a capsule are preferably formed of a soluble ingredient, such as, for example, gelatin (animal-based product), starch, hydrophillic polymer or hydroxypropyl methyl-cellulose (HPMC), which provides a barrier for containing the active ingredient or medicament, in powder or liquid form, within the internal periphery of the capsule walls. Traditionally, hard gelatin capsules may be manufactured by dipping plates of stainless steel pins into a pool of gelatin solution. The pins are then removed from the gelatin and rotated while the gelatin is dried in a kiln with forced, humidity-controlled air. Once dried, the gelatin capsules are typically stripped from the pins, trimmed to a suitable length and then joined together (e.g. base and cap) and packaged for production use.
With the advent of automated encapsulation machinery, the responsibility to produce encapsulated products shifted mainly to industrial manufacturers. Contemporaneous with the development of the encapsulation industry, those skilled in the art have advanced the state of the encapsulation art. For example, several significant improvements in encapsulation technology have been seen over the last forty years. These technological improvements have included, for example, the development of soft elastic capsules, film-coating techniques, micro-encapsulation and multiple-compartment technology.
Soft elastic capsules, often referred to as soft gelatin capsules, were developed in an effort to provide means for encapsulating liquids and other medicaments which are typically poorly soluble in water. In preferred design, soft elastic capsules are made from a thicker and more plastic gelatin having an increased flexibility due to the addition of a polyol, such as glycerin or sorbitol. The addition of such plasticizers has been found, however, to have the potential disadvantage of increasing the risk for microbial growth. Thus an antimicrobial, such as a paraben or sorbic acid, may be added to the soft elastic capsule shell in order to address any microbial concern.
Prior art film-coating techniques generally involve a plating process, whereby a thin, uniform film may be deposited onto the outer surface of the of the delivery vehicle (e.g., tablet or capsule). Several successive layers may be deposited onto the outer surface of the vehicle, if desired, in an effort to facilitate various desirable properties. For example, sugar-coating, a precursor to film-coating, has been used by those skilled in the art for more than one hundred years to make tablets more palatable. Other advantages or properties of film-coating may include for example, but not by way of limitation, protection from moisture, oxidation, controlling microbial contamination and inhibiting modification of the chemical properties of the active ingredient. As further appreciated by those skilled in the art, prior art film-coating may form an interfacial barrier between two chemicals or chemical compounds that might otherwise react when they come into contact.
Enteric coatings and sustained-release formulations are contemplated as variations on prior art film-coating techniques. In particular, enteric coating describes a process where the delivery vehicle (e.g., tablet or capsule) is coated with one or more layers of chemicals that are somewhat resistant to extreme pH conditions. For example, conditions of extremely low pH are commonly encounter in the stomach. Many active ingredients or medicaments are in the form of a pharmaceutical salt and thus highly susceptible to ionization in the presence of hydrogen ions. Thus, the presence of an enteric coating generally provides a level of protection as to degradation of the active ingredient or medicament until transit from the stomach into the small intestine is accomplished.
Film coatings have also led to the development of delivery vehicles (e.g., tablets and capsules) having sustained-release properties. Mixtures of waxes, cellulose, silicone and similar resins have been found useful by those skilled in the art for creating-sustained release coatings. In principle, these prior art coatings function to delay the release of the active ingredient or medicament to the targeted body system, thereby facilitating a timed, absorption rate in the body. Furthermore, the entire daily dosage of an active or medicament may be contained in a single, sustained-release delivery vehicle (e.g., tablet or capsule), whereas the immediate absorption of the entire dosage could possibly lead to an overdosage of the medicament. Thus, by layering quanta of medicament with differential coatings, the dosage undergoes a controlled release over specified time period. The application of sustained-release film coating technology therefore may inherently facilitate the delivery of a total daily dosage amount of an active or medicament to be released to the body in controlled increments.
Over the last several years, a considerable amount of attention has been focused on the further development of multi-compartment capsule technology for the delivery of therapeutic and diagnostic agents. Series formulations teach the use of membranes or other types of barriers to cordon a line of separate chambers within a single encapsulating shell. As appreciated, the purpose of such multi-compartment delivery devices is the administration of multiple dosages. Moreover, multiple-compartment delivery mechanisms of the prior art were developed to circumvent or diminish the effects of harsh pH environments within humans. For example, the prior art contemplates a hard capsule formulation which contains three different compartments of active medicaments for administration to the vaginal and rectal areas. In preferred structure, the formulation outer, rapid-release layer may contain an active medicament and excipient; the middle, intermediate-release layer may include a powder form of active medicament; and the inner, slow-release layer may contain pellets or granules of active medicament.
Also taught in the prior art are multi-compartment capsules having groups of spheroids with pH-dependent coatings which are encapsulated within a hard gelatin shell and provided for treating female yeast infection. The first spheroid is preferably uncoated and may be in a powder form; the second spheroid may contain a pH sensitive coat; and the inner spheroid may include a pH insensitive coat.
In addition to pH-sensitive coatings, hydrogels and other gastric retention technologies have been developed by those skilled in the art in an effort to retard the progression of the delivery vehicle during enteric transit. This retarding action, presumably, allows the full amount of active medicament to be released and/or targeted to a specific area of the gastrointestinal tract. Hydrogel and related gastric retention devices of the prior art generally rely upon the imbibing of water into a center core which is filled with cellulose or similar water absorbent material. In preferred operation, the material swells and releases multiple compartments of active medicament. The concept of using bulk size to slow transit of single active medicament in a single physical state is thus appreciated.
In an effort to administer active ingredients or medicaments to a specific location in the body to treat a specific disorder caused by a specific pathogen, those skilled in the art have used targeted-release systems using multi-compartment capsular technology. For example, a method for carrying out a triple therapy against the microorganisms Helicobacter pylori, a known infectious agent which is believed largely responsible for the development of gastric ulcer disease, was developed which comprises the steps of oral administration of a pharmaceutical dosage form comprising an internal capsule placed inside an external capsule, wherein the external capsule comprises a soluble salt of bismuth and a first antibiotic, and the internal capsule comprises a second antibiotic. In addition, multi-compartmental capsules were developed which combine, a nutrient supplement with a viable direct-fed microbial (i.e., gastrointestinal microorganisms, including bacteria, live cell yeasts, fungi or a combination thereof) for the purpose of treating livestock for feeding disorders and improving feed efficiency.
A disadvantage with prior art encapsulation technology is when the base and corresponding cap of a capsule are joined, dead space volume is typically created within the internal periphery of the capsule. Internal capsular dead space may be filed with an air bubble which may ultimately react with one or more of the active ingredients or medicaments introduced within the capsule, thereby potentially degrading the quality and effectiveness of the active ingredients.
Although the prior art discloses multiple compartment, capsular delivery technology, these manifestations generally includes one of two approaches. For example, one approach contemplates the introduction of a single active or medicament into multiple capsular compartments to vary the temporal release of the medicament and ultimately the absorption rate into the body. Another approach contemplates the introduction of a plurality of active ingredients or medicaments into different compartments of a single capsule for delivery to a specific area of the body to treat a targeted illness or condition.
The use or contemplation of multiple-compartment capsular delivery apparatus or methods which deliver different physical forms of the same active or medicament, or a variation in physical forms of different actives or medicaments in a single dosage, however, has not heretofore been contemplated in the art. As appreciated by those skilled in the art, active ingredients or medicaments may take the physical form of a solid (e.g., pill, tablet, capsule (both hard and soft elastic), powder, granulation, flakes, troches (lozenges and pastilles), suppositories and semi-solid ointments, pastes, emulsions and creams), a liquid (e.g., solution, spirits, elixir, syrups, sprays and fluid extracts), a gas or a dispersion. A dispersion is a system in which a dispersed phase is distributed through a continuous phase (e.g., aerosols (liquid or solid in gas), suspensions (solid in liquid), emulsion (liquid in liquid), foam (gas in liquid), solid foam (solid in gas) or gel (liquid or solid in solid)). Dispersions can be classified as molecular, colloidal and coarse, depending on size. In many circumstances, however, the different physical forms or phases of more than one active ingredient or medicament may not be suitably combined or mixed together without altering the individual desirable properties of the active ingredient or medicament. For example, although it would be possible and desirable to formulate a dispersion by combining a first active ingredient in the solid state with a second active ingredient that exists as a liquid, adverse chemical interactions between the active ingredients may adversely affect various characteristics of the ingredients, including but not limited to, their shelf lives. The resulting chemical decomposition—and the potential formation of any unwanted side products—could result in diminished drug potency or even toxicity to a patient.
Additionally, the physical properties of crystalline active ingredients could be drastically altered in scenarios where it is desirable to co-administer a crystalline active ingredient with a liquid or semi-liquid different active ingredient. In this context, the control of physical properties such as active ingredient dissolution rate and solubility is often a critical factor in determining the overall bioavailability of the active ingredient. It is well established in the art that different polymorphs or solvates of the same crystalline active ingredient exhibit dramatically different solubility and dissolution rates. Thus, combining a crystalline active agent with a liquid or semi-liquid active agent could give rise to an equilibrium between concentrations of different polymorphs and/or solvates of the crystalline active ingredient, and thereby frustrate efforts at tailoring an active ingredient mixture to its intended purpose as a medicament.
Another shortcoming with co-administering plural active ingredients in different physical forms in an intimate mixture is the potential for adverse in vivo drug-drug interactions upon administration. The desire to co-administer these active ingredients would be offset by the one active ingredient, for example as in a liquid or semi-liquid (e.g., a paste, solution, or syrup) form, becoming rapidly available. In this context, the active ingredient may adversely react with a co-administered drug, for example a less bioavailable solid or semi-solid, in a physiological environment. Thus, the true therapeutic benefit resulting from the pharmacological effects of the individual active agents may never be realized. It would be desirable to co-administer plural active ingredients while insuring against the potential of such harmful drug-drug interactions.
Providing active ingredients or medicaments in separate capsules may also be undesirable in the context of patient compliance. Geriatric and pediatric populations in particular disfavor the handling and consumption of multiple capsules of active ingredients. Patient compliance is essential in maintaining patient health in many dosage regimens. For example, deviations from accurate dosing and consistent consumption of immunosuppressant therapies can result in severe or even lethal consequences for a patient. Providing combined dosages of active ingredients would result in fewer capsules a patient or consumer would have to take, and thereby contribute to an overall increase in compliance.
Therefore, it would be desirable to provide a multi-compartment capsular delivery apparatus and methods that provide active ingredients or medicaments having diverse physical properties (e.g., solid, liquid, gas or dispersion), which mayor may not be properly combined or stored together into a unitary structure (i.e., multi-compartment capsule) for usage in a single dosage form. The present invention, in overcoming the shortcomings of the prior art, satisfies these and other objectives.
The art and practice of pharmacy can be divided into four distinct divisions. Pharmacology is the study of interactions occurring between the pharmacologic agent, or medicament and specific targeted cells in the body. More specifically, the interaction between an active agent and a cellular receptor along with the resulting change in cell physiology is examined. Medicinal chemistry is largely concerned with the identification of naturally occurring and synthetic compounds which possess medicinal characteristics.
Pharmacotherapeutics is the holistic application of pharmacy practice to specific pathologies, illnesses, and other body functions. Finally, Pharmaceutical science ascertains or regulates the composition of medicinal substances, and is largely directed to the development of new mechanisms for delivering chemicals and biomolecules into animals and humans. A subcategory of pharmaceutical science is called pharmacokinetics and sometimes generally referred to as biopharmaceutics.
A.D.M.E. is an acronym often used to describe the four essential components to pharmaceutical science: absorption, distribution, metabolism, and elimination, respectively. One way to differentiate between pharmacology and pharmaceutical science is that the former is primarily concerned with the effect of the medicament on the body, whereas, the latter is primarily concerned with the delivery and time-course of the medicament on its journey through the body.
In clinical applications, chemicals and biomolecules are often referred to as active ingredients or medicaments. Medicaments may include “pharmaceuticals, nutraceuticals, biotechnicals, vitamins, minerals and dietary supplements.” Oral administration is the most frequent route for delivery of medicaments. Medicaments may be orally administered in a variety of physical states, including, solid, liquid, dispersion, and gaseous forms. As appreciated, tablets and capsules are the most common vehicle for oral delivery of medicaments.
Frequently, a medical or surgical patient may receive a plurality of concurrent medicaments. Data has been accumulated to demonstrate that patients undergoing a surgical procedure may receive ten (10) or more medicaments during the surgery and the resulting surgical recovery period. Some patients who have undergone organ transplantation or who have contracted human immunodeficiency virus (HIV) may receive three (3) or more medicaments which require multiple administrations per day. HIV patients often receive many more than three (3) medicaments. These medicaments may be necessary for the treatment of several conditions occurring in a plurality of organ systems or they may be necessary to treat a single condition or some combination thereof.
In some cases, it may be desirous to combine a plurality of medicaments because of a synergistic interaction between a plurality of medicaments. This synergy may enhance the efficacy of one or more of the medicaments. Medicaments may be combined to increase the intensity of response or efficacy. A plurality of medicaments, in combination, may be homergic (i.e., elicit the same quality of effect). In many cases, a plurality of homergic medicaments may also be homo dynamic (i.e., interact with the same receptor). A plurality of homergic medicaments may be additive, supra-additive and infra-additive. A plurality of combined medicaments which do not produce the same quality of response may be called, heterergic. When heterergy is found to be a positive effect (i.e., at least one medicament enhances the response to another medicament), this may be called synergism and is sometimes called synergy.
In further cases, it maybe desirous to combine a plurality of medicaments to decrease their individual dosages and possibility for toxicity. It may also be desirous to combine a plurality of medicaments to target the treatment of a disease, illness or condition from divergent angles. It may be desirous to combine a plurality of medicaments to minimize the side effects and adverse effects of one or more medicaments. It may be still further desirous to combine a plurality of medicaments to alter the pharmacokinetic characteristics of one or more medicaments. For example, alterations in the absorption, distribution, metabolism or elimination of one or more medicaments.
Fixed combinations of a plurality of medicaments have been generally disfavored due to any number of perceived disadvantages. These disadvantages may include, for example: (1) complicating the interpretation of safety and efficacy in therapeutic regimens, (2) there may be inter-patient differences to fixed combinations, (3) there may be difficulties in dosage titration, and (4) the delivery platforms for fixed combinations have generally been found to be uneconomical to produce.
On the other hand, fixed combinations of a plurality of medicaments may lead to several therapeutic advantages, including, for example, but not by way of limitation: (1) increasing patient compliance with therapy, (2) increasing efficacy by optimizing timing of medicaments, (3) minimization of side effects and adverse effects, (4) enhancement of pharmacokinetic characteristics of one or more medicaments in a fixed combination, (5) increased patient quality of life, (6) optimization of institutional resources by minimizing the amount of medicament administrations, and (7) minimizing patient length of stay in institutional facilities by optimizing therapy.
Prior art therapeutic technologies contain isolated examples of pharmaceutical formulations containing fixed combinations of medicaments. However, therapeutic technologies of the prior art teach a fixed combination, wherein a plurality of medicaments are placed into a single receiving chamber in the delivery formulation (i.e., no separation between the plurality of medicaments).
In view of the state of the technology as it exists today, generally, therapeutic apparatus and methods are needed to provide a plurality of medicaments for medical and surgical conditions, as well as maintenance of normal health function for delivery to animals and humans using a multi-chambered delivery apparatus. Such apparatus and methods for delivering a plurality of medicaments to animals and humans using a multi-chambered delivery apparatus are contemplated herein.